Recurrent herpes simplex labialis, otherwise known as cold sores, is a viral infection commonly experienced by many adults.  It is caused by the Herpes Simplex Virus (generally HSV-1), which resides within nerves after the initial infection that generally occurs in childhood1.  The virus remains silent until it erupts in response to stimuli such as stress, sunlight, fever, respiratory tract infections, and sunlight2.  This results in the formation of the “cold sore”, a red, swollen vesicle that occurs on the lips and around the mouth. It eventually crusts over and heals in around 7-10 days without treatment3.  For treatment to be effective, it generally must begin in the prodrome phase (the initial onset phase) – a period of tingling, itching, numbness, or burning at the site of the legion before it erupts3.

Young man with cold sore

Let’s face it, there are worse things to wake up to than cold sores.  Many cold sore episodes are mild and resolve on their own.  Having said that, cold sores are notorious for appearing at the worst possible times, they are uncomfortable, painful and in some cases occur more frequently causing awkwardness and embarrassment for some.  All available treatment options of cold sores need to be initiated as early as possible and within a narrow time frame in order to be effective.  So an effective non-prescription (over-the-counter) cold sore remedy could be a possible treatment option.  We ask, is Abreva® a viable treatment option? This article compares to Abreva® to other antiviral therapy.

What Is Abreva® and How Does It Work?

Abreva®, known as n-docosanol, is a cream available without a prescription in Canada for the treatment of recurring cold sores and is classified as ‘antiviral therapy’.  In order for the cold sore to erupt, the virus needs to get into our cells where it would then grow.  Abreva® prevents entry of the virus into the cells.  Abreva® works differently than other antiviral medication for cold sores, making it potentially useful in viruses resistant to other treatments3.  It is applied five times a day until the cold sore has fully healed3.

What Does the Evidence Say?

Unfortunately, there are only a handful of studies evaluating the efficacy of Abreva® for cold sores.  In one study, if Abreva® was used in the prodromal phase (the initial phase when redness/swelling appeared) it reduced the healing time by 4.3 days3, 4.  If it was applied during the later stages of infection, it did not reduce healing time3, 4.  However, the study ultimately was very small, making it hard to truly determine the benefit. Another study, which was significantly larger, found that if applied during the prodromal (very early) phase, Abreva®, reduced healing time by 0.72 days2.  This same study also found it reduced the amount of time it took for the pain to stop2.  Although this doesn’t seem like a lot of time, it may actually be meaningful to some3 because the life span of a cold sore is so short!  How does Abreva® compare to prescription antiviral options?  When compared to oral antivirals, Abreva® is not as effective in reducing the healing time (so prescription products are found to work better).  In addition, some prescription antivirals are conveniently given as a single dose or a one day treatment compared versus Abreva® requires application five times a day3.  Other topical antivirals are by prescription only.  They are found to be at least as effective when compared to Abreva® but may be applied for a shorter time3. Keep in mind that prescription antivirals (oral or topical antivirals) also cost more than Abreva®. There are other topical products available over-the-counter to help cold sores but are not classified as antiviral therapy (not discussed in this article!).

Are There any Safety Concerns?

Abreva® is a very well tolerated and safe treatment for cold sores.  Headaches were the most common side effect (5.9%); otherwise there were no significant adverse effects noted2, 3.

Bottom Line

Abreva® has been shown to be safe and effective for the treatment of cold sores.  However, when compared to other prescribed options, it is not as effective or as easy to administer.  Remember that there is a very small window for the initiation of treatment of all cold sore medications, many patients may not be able to get a prescription in time. In this situation, Abreva® may be a good choice as it is available without a prescription in Canada and shown to be moderately effective with limited side effects for the treatment of recurrent cold sores. Make sure to use it right when you feel the cold sore coming on!

Author:

Matthew Timms, BSc. Pharm

Edited and Reviewed by The Health Aisle Team

 

References

  1. Opstelten, W., Knuistingh, N., & Eekhof, J. (2008). Treatment and prevention of herpes labialis. Canadian Family Physician, 54(12): 1683-1687.
  2. Sacks et al. (2001). Clinical efficacy of topical docosanol 10% cream for herpes simplex labialis: A multicenter, randomized, placebo-controlled trial. Journal of the American Academy of Dermatology, 45(2): 222-300.
  3. Treister, N. & Woo, S. (2010). Topical n-docosanol for management of recurrent herpes labialis. Expert Opinion on Pharmacotherapy, 11(5): 853-860.
  4. Habbema, L., Deboulle, K., Roders, G.A., & Katz, D.H. (1996). n-Docosanol 10% cream in the treatment of recurrent herpes labialis: A randomized, double-blind, placebo-controlled study. Acta Dermato-Venereologica, 76(6): 479-481.